Are you talking about carbon-coatings? If so, in my experience tobacco, heat and time are better than any chemical compound on the market...but if you do insist on painting the inside of your bowls, for the love of all things holy, avoid sodium silicate like the plague it is!
Here is a good way to get you some cake with a quickness. I discovered it by accident.
i have been experimenting with casing raw leaf tobacco and my first batch I used way too much honey. It stuck to the sides of my pipe like glue. It also sweetened the pipe so it was an overall good mistake. The ash of the bowls I smoked after the overcased honey tobacco stuck to the walls of the bowl building cake very quickly. I suggest taking some tobacco and throwing it in a bowl. Then take a mix of 50/50 honey and water and drizzle it on the tobacco then toss it like a salad. Allow it to dry out a bit then pack it and smoke it very slowly. It will burn very hot so be careful. After this bowl you will build the cake you want with a quickness... Good luck!!
doesn't hurt to shake the left over ash and dottle in the chamber afterwards... mix it with your pipe tool, and put your thumb on the chamber, shake shake, let the pipe rest 12 hours.
in other words, what everyone is saying is... you don't need false char, just patience and a little technique.
False char is grey in color. You apply it like paint to the inside of a bowl of a pipe. It is not usually found in high quality pipes but it dries inert and fills in yiny scratches etc. and dries to form a very smooth uniform surface that carbon cake can form on.